text: Insertion Sort for Doubly Linked List | C ++ implementation for insertion Sort on a doubly linked list ; Node of a doubly linked list ; function to create and return a new node of a doubly linked list ; allocate node ; put in the data ; function to insert a new node in sorted way in a sorted doubly linked list ; if list is empty ; if the node is to be inserted at the beginning of the doubly linked list ; locate the node after which the new node is to be inserted ; Make the appropriate links ; if the new node is not inserted at the end of the list ; function to sort a doubly linked list using insertion sort ; Initialize ' sorted ' - a sorted doubly linked list ; Traverse the given doubly linked list and insert every node to ' sorted ' ; Store next for next iteration ; removing all the links so as to create ' current ' as a new node for insertion ; insert current in ' sorted ' doubly linked list ; Update current ; Update head_ref to point to sorted doubly linked list ; function to print the doubly linked list ; function to insert a node at the beginning of the doubly linked list ; allocate node ; put in the data ; Make next of new node as head and previous as NULL ; change prev of head node to new node ; move the head to point to the new node ; Driver program to test above ; start with the empty doubly linked list ; insert the following data
code: #include <bits/stdc++.h> NEW_LINE using namespace std ; struct Node { int data ; struct Node * prev , * next ; } ; struct Node * getNode ( int data ) { struct Node * newNode = ( struct Node * ) malloc ( sizeof ( struct Node ) ) ; newNode -> data = data ; newNode -> prev = newNode -> next = NULL ; return newNode ; } void sortedInsert ( struct Node * * head_ref , struct Node * newNode ) { struct Node * current ; if ( * head_ref == NULL ) * head_ref = newNode ; else if ( ( * head_ref ) -> data >= newNode -> data ) { newNode -> next = * head_ref ; newNode -> next -> prev = newNode ; * head_ref = newNode ; } else { current = * head_ref ; while ( current -> next != NULL && current -> next -> data < newNode -> data ) current = current -> next ; newNode -> next = current -> next ; if ( current -> next != NULL ) newNode -> next -> prev = newNode ; current -> next = newNode ; newNode -> prev = current ; } } void insertionSort ( struct Node * * head_ref ) { struct Node * sorted = NULL ; struct Node * current = * head_ref ; while ( current != NULL ) { struct Node * next = current -> next ; current -> prev = current -> next = NULL ; sortedInsert ( & sorted , current ) ; current = next ; } * head_ref = sorted ; } void printList ( struct Node * head ) { while ( head != NULL ) { cout << head -> data << " ▁ " ; head = head -> next ; } } void push ( struct Node * * head_ref , int new_data ) { struct Node * new_node = ( struct Node * ) malloc ( sizeof ( struct Node ) ) ; new_node -> data = new_data ; new_node -> next = ( * head_ref ) ; new_node -> prev = NULL ; if ( ( * head_ref ) != NULL ) ( * head_ref ) -> prev = new_node ; ( * head_ref ) = new_node ; } int main ( ) { struct Node * head = NULL ; push ( & head , 9 ) ; push ( & head , 3 ) ; push ( & head , 5 ) ; push ( & head , 10 ) ; push ( & head , 12 ) ; push ( & head , 8 ) ; cout << " Doubly ▁ Linked ▁ List ▁ Before ▁ Sortingn " ; printList ( head ) ; insertionSort ( & head ) ; cout << " nDoubly ▁ Linked ▁ List ▁ After ▁ Sortingn " ; printList ( head ) ; return 0 ; }